遇溺警報系統Poseidon drowning detection system
https://en.wikipedia.org/wiki/Poseidon_drowning_detection_system
http://www.drowningprevention.com.au/
Poseidon - Drowning Prevention youtube
https://www.youtube.com/playlist?list=PLmXNY8D9BvlqWSV9MJl25Uws3soSG4T7S
https://www.youtube.com/watch?v=aR1h87sGZxs
https://www.youtube.com/user/MaytronicsAU
